In particular aspects, the invention pertains to a particle detection system and methods for the detection and identification of particles in a sample.
Particle detection and monitoring can be of great importance for assessing environmental health risks. Various types of particles, including biological pathogens, other types of biological particles, allergens, and pollutants, can pose serious health and safety concerns. Many of these particle types can exist naturally in the environment, some of which become a health risk only at increased levels. Others can be artificially introduced into the environment by human activities including for example, industrial activities, biological warfare and bio-terrorism. The ability to detect and identify potentially harmful particles in an environment can be desired for timely particle containment and decontamination of an affected area.
Often it is difficult to distinguish viable bioparticles from nonviable bioparticles or inert particles. Current methods directed toward such determination are often unreliable and time consuming. Such problems may result in a potential for increased exposure. Additionally, the methods presently available can be cost-prohibitive due to such factors as the need for specialized personnel, or expensive reagents, equipment, or analysis techniques.
It would be desirable to develop methods for detecting bioparticles and methods for distinguishing bioparticles from non-bioparticles. It would also be desirable to develop methods to monitor particle levels in an environment.
In one aspect, the invention encompasses a particle detection system for detecting bioparticles in a sample. The particle detection system includes a sample collector having a sample outlet. The particle detection system also includes a sensor device which receives the sample and measures at least one type of photoacoustic signal from the sample.
In one aspect, the invention encompasses a system for distinguishing biological particles from non-biological particles in a sample. The system includes a chamber that retains the sample and a laser that directs emitted laser light through the sample. A transducer mounted proximate the chamber receives acoustic signals from the sample. A fluorescence detector mounted proximate the sample receives light emitted by the sample. The system utilizes the information received from the sample by the fluorescence detector and by the transducer to distinguish biologically active particles from non-biologically active particles.
In one aspect, the invention encompasses a method of screening a sample for the presence of one or more particle types. A sample is subjected to laser light to produce at least one photonic response and at least one acoustic response which are measured to establish a sample composite data set. The sample composite data set is compared to a signature data set which is obtained from a control sample having a known particle composition. The signature data set is a fingerprint of the known composition of the control sample. Comparison of the signature data set and the sample composite data set is indicative of a presence or absence within the sample of particles identified by the signature data set.
In one aspect, the invention encompasses a method of detecting a change in the particle composition within a test area. Particles are collected and concentrated into a volume of liquid to produce a test sample. A sample is provided into a sensor device where one or more types of photoacoustic signals are induced from the test sample. A photoacoustic measurement is obtained and compared to reference data which is generated from one or more reference samples that have been obtained and processed identically to the test sample.